Transmitting ip packets originating in a wireless station when the ip packets are destined for delivery to multiple destinations via an access point

ABSTRACT

A wireless station of a wireless network generates a single layer-2 frame containing multiple layer-3 packets in its payload. Each of the multiple layer-3 packets is destined to a corresponding different destination. The wireless station transmits the layer-2 frame to an access point (AP) of the wireless network. The AP receives the layer-2 frame, disassembles the payload into individual layer-3 packets, and transmits each of the individual layer-3 packets separately towards the corresponding destinations. In an embodiment, the wireless network is according to IEEE 802.11 standards, each layer-3 packet is an IP packet, and the layer-2 frame is a MAC frame.

BACKGROUND

Technical Field

Embodiments of the present disclosure relate generally to wirelessnetworks, and more specifically to delivering of IP (Internet Protocol)packets originating in a wireless station when the IP packets aredestined for delivery to multiple destinations via an access point.

Related Art

A wireless network may be viewed as having wireless stationscommunicatively coupled on wireless path to each other via an accesspoint (AP). The wireless stations are either the source machines or(target) destination machines for the data packets (from the viewpointof the wireless network), with the AP operating as a switching devicewhich receives each data packet from a source station and forwarding thepacket to the destination station. Wireless networks are implementedusing standards such as IEEE 802.11, as is well known in the relevantarts.

Wireless stations often encode data packets in the form of InternetProtocol (IP) packets. An IP packet is characterized by a destination IPaddress, which specifies the destination machine. IP is commonly usedwhen the data may need to be communicated to systems outside of thewireless network. In a known configuration, an AP is coupled with awired path to a router-type device, which extends the connectivity ofthe wireless stations to devices on the Internet, in a known way.

A wireless station may need to transmit multiple IP packets, with eachpacket destined to a different destination. For example, a wirelessstation may take multiple measurements corresponding to differentparameters, and the measured value for each parameter may need to besent to a different target. Assuming such different parameters aretemperature, pressure, water level, etc., temperature measurements maybe sent to one target, pressure measurements may be sent to anothertarget, and water level measurements may be sent to another target.

It is generally desirable that access points send such multiple IPpackets efficiently, as suited in the corresponding environments.

BRIEF DESCRIPTION OF THE VIEWS OF DRAWINGS

Example embodiments of the present invention will be described withreference to the accompanying drawings briefly described below.

FIG. 1 is a block diagram of an example environment in which severalaspects of the present disclosure may be implemented.

FIG. 2A is a flow chart illustrating the manner in which a wirelessstation (STA) of a wireless network transmits IP packets, in anembodiment of the present disclosure.

FIG. 2B is a flow chart illustrating the manner in which an access point(AP) of a wireless network processes a layer-2 frame containing multipleIP packets, in an embodiment of the present disclosure.

FIG. 3 is a block diagram showing the details of a communicationprotocol stack in a STA of a wireless network, in an embodiment of thepresent disclosure.

FIG. 4 is a diagram illustrating the contents of a layer-2 frametransmitted by a STA of a wireless network, in an embodiment of thepresent disclosure.

FIG. 5 is a diagram illustrating the contents of a layer-2 frametransmitted by a STA of a wireless network according to IEEE 802.11standards, in an embodiment of the present disclosure.

FIG. 6 is a diagram illustrating the sub-fields of a ‘frame controlfield’ of an IEEE 802.11 MAC frame transmitted by a STA, in anembodiment of the present disclosure.

FIG. 7 is a block diagram showing the details of a communicationprotocol stack in an AP of a wireless network, in an embodiment of thepresent disclosure.

FIG. 8 is a block diagram illustrating the implementation details of awireless device in an embodiment of the present disclosure.

In the drawings, like reference numbers generally indicate identical,functionally similar, and/or structurally similar elements. The drawingin which an element first appears is indicated by the leftmost digit(s)in the corresponding reference number.

DETAILED DESCRIPTION 1. Overview

A wireless station of a wireless network generates a single layer-2frame containing multiple layer-3 packets in its payload. Each of themultiple layer-3 packets is destined to a corresponding differentdestination. The wireless station transmits the layer-2 frame to anaccess point (AP) of the wireless network. The AP receives the layer-2frame, disassembles the payload into individual layer-3 packets, andtransmits each of the individual layer-3 packets separately towards thecorresponding destinations. In an embodiment, the wireless network isaccording to IEEE 802.11 standards, each layer-3 packet is an IP packet,and the layer-2 frame is a MAC frame.

Several aspects of the invention are described below with reference toexamples for illustration. It should be understood that numerousspecific details, relationships, and methods are set forth to provide afull understanding of the invention. One skilled in the relevant arts,however, will readily recognize that the invention can be practicedwithout one or more of the specific details, or with other methods, etc.In other instances, well-known structures or operations are not shown indetail to avoid obscuring the features of the invention.

2. Example Environment

FIG. 1 is a block diagram representing an example environment in whichseveral aspects of the present disclosure can be implemented. Theexample environment is shown containing only representative devices andsystems for illustration. However, real-world environments may containmore or fewer systems/devices. FIG. 1 is shown containing access point(AP) 110, wireless stations (STA) 120, STAs 130A-130P, servers140A-140N, internet 150, and sensors 160A-160M. The wireless network(WLAN) containing AP 110, STA 120 and STAs 130A-130P may be referred toas an infrastructure basic service set (BSS) 190.

Servers 140A-140N represent computing devices that provide desired userapplications. In an embodiment, each of servers 140A-140N is designed toprocess a corresponding set of measurements (e.g., temperature,pressure, etc.) received from STA 120 based on respective userapplications. Each of servers 140A-140N is connected to internet 150,and can communicate using IP (Internet Protocol) with otherdevices/systems in internet 150, as well as with STA 120 and STAs130A-130P. The servers may process IP packets received from otherdevices in a desired manner and present the results of the processing toa user/administrator.

Internet 150 extends the connectivity of devices (STA 120 and STAs130A-130P) in BSS 190 to various devices/systems (e.g., servers140A-140N) connected to, or part of, internet 150. Internet 150 is shownconnected to AP 110 (which may be viewed as operating as a border routeras well) through a wired path 119. Internet 150 may be implemented usingprotocols such as IP (Internet Protocol). In general, in IPenvironments, an IP packet is used as a basic unit of transport, withthe source address being set to the IP address assigned to the sourcesystem from which the packet originates and the destination address setto the IP address of the destination system to which the packet is to beeventually delivered. The IP packet is encapsulated in the payload oflayer-2 packets when being transported across WLANs.

An IP packet is said to be directed to a destination system when thedestination IP address of the packet is set to the IP address of thedestination system, such that the packet is eventually delivered to thedestination system. When the packet contains content such as portnumbers, which specifies the destination application, the packet may besaid to be directed to such application as well. The destination systemmay be required to keep the corresponding port numbers available/open,and process the packets with the corresponding destination ports.

Each of STAs 120 and STAs 130A-130P represents an end device that is asource or destination of data elements, when viewed from the perspectiveof the wireless network of FIG. 1. The data elements are transmitted to(and received from) AP 110 in layer-2 (medium access control (MAC))frames in accordance with 802.11 family of standards. While the dataelements are described as being destined only to servers 140A-140N inthe description below, such servers can be placed in conjunction withsome of the STAs in BSS 190 in alternative embodiments.

The STAs 130A-130P may communicate with each other via AP 110 using IP,with IP addressing being used for communications with servers 140A-140Nas well. Thus, each of STA 120 and STAs 130A-130P is assigned a uniqueIP address using DHCP type protocols well known in the relevant arts. AP110, in addition to performing operations consistent with thecorresponding wireless standard, operates as an IP router to forwardpackets received from the other devices of FIG. 1 to the appropriatedestination or next-hop device.

In an embodiment, AP 110, STA 120 and STAs 130A-130P form a basicservice set (BSS) 190 consistent with IEEE 802.11 family of standards(including amendments such as 802.11a, 802.11b, 802.11i, 802.11n, etc.).However, in other embodiments, AP 110, STA 120 and STAs 130A-130P may bedesigned to operate according to other wireless standards, such as forexample, IEEE 802.15.4. The antenna of STA 120 is shown numbered as 125.Antennas of other wireless devices of FIG. 1 are indicated by thecorresponding symbol, but not numbered.

Each of sensors 160A-160M generates measurements (data values)representing a parameter of interest, such as for example, temperature,pressure, etc., of/in corresponding objects. Each of sensors 160A-160Mforwards the respective data values to STA 120 on a wired or wirelesspath (not shown). STA 120 is designed to forward the data values to oneor more of desired destinations STA 130A-130P and/or servers 140A-140Nin the form of IP packets.

According to a prior technique, STA 120 may use a separate MAC frame fortransmitting data values as IP packets to different servers 140A to140N. In other words, a single MAC frame would contain only a single IPpacket (containing data values) destined to only a single server in suchan approach. Assuming the temperature reading is to be transmitted toserver 140A, STA 120 forms an IP packet containing the temperaturemeasurement in its payload, and the destination IP address of server140A in the destination IP address field of the IP packet (with theother fields of the IP packet containing corresponding entries). STA 120then encapsulates the IP packet thus formed in a layer-2 frame, andtransmits the layer-2 frame to AP 110.

AP 110 extracts the IP packet from the layer-2 frame, and forwards theIP packet to a next-hop device in the route to server 140A. For anotherdata value to another server, STA 120 would similarly form anotherlayer-2 frame with encapsulated IP packet, and transmit the layer-2frame to AP 110, which then forwards the encapsulated IP packet alongthe path to the corresponding destination.

The prior approach may have a drawback in that STA 120 would have tocontend for the wireless transmission medium prior to transmitting eachIP packet, and the prior approach may therefore be inefficient in termsof power consumption and/or time required for overall data transfer.

Aspects of the present disclosure overcome the drawback noted above, asdescribed next with respect to a flowchart.

3. IP Packet Aggregation

FIG. 2A is a flow chart illustrating the manner in which a STA of awireless network transmits multiple IP packets efficiently, in anembodiment of the present disclosure. Merely for illustration, theflowchart is described below as being performed in STA 120. However, thefeatures can be implemented in other STAs also, as well as in otherenvironments, without departing from the scope and spirit of variousaspects of the present invention, as will be apparent to one skilled inthe relevant arts by reading the disclosure provided herein.

In addition, some of the steps may be performed in a different sequencethan that depicted below, as suited to the specific environment, as willbe apparent to one skilled in the relevant arts. Many of suchimplementations are contemplated to be covered by several aspects of thepresent disclosure. The flow chart begins in step 201, in which controlimmediately passes to step 210.

In step 210, STA 120 assembles multiple IP packets, with each IP packetdestined to a corresponding IP destination. The payloads of each of theIP packets may contain one or more measurement values (data values)received from one or more of sensors 160A-160M. It should be appreciatedthat the IP packets themselves can be formed within STA 120 or receivedfrom corresponding sensors (in which case each IP packet containsmeasured values only from that sensor). Irrespective of where each IPpacket is formed, the IP packets are assumed to be available for furtherprocessing, as described below. Control then passes to step 220.

In step 220, STA 120 generates a single layer-2 (i.e., MAC) frame withthe assembled IP packets in the payload of the MAC frame. In otherwords, a single MAC frame contains multiple IP packets, with each IPpacket being destined to potentially different destination (server140A-140N). Control then passes to step 230.

In step 230, STA 120 transmits the single MAC frame to AP 110. Controlthen passes to step 249, in which the flowchart ends.

Although in the flowchart of FIG. 2A, multiple IP packets are describedas being placed in the payload of a single MAC packet, the technique canbe extended in general to place multiple layer-3 packets in the payloadof a layer-2 packet, which is then transmitted on a wireless medium. Asis well known in the relevant arts, a layer-2 packet is a packet that isdestined to a next-hop device (with respect to the transmitter of thelayer-2 packet) within a network, while a layer-3 packet is a packetthat is designed to be routed to a destination device one or morenetworks away from the transmitter in the network.

FIG. 2B is a flow chart illustrating the manner in which an AP of awireless network processes a MAC frame containing multiple IP packets,in an embodiment of the present disclosure. Merely for illustration, theflowchart is described below as being performed in AP 110. However, thefeatures can be implemented in other environments, without departingfrom the scope and spirit of various aspects of the present invention,as will be apparent to one skilled in the relevant arts by reading thedisclosure provided herein. In addition, some of the steps may beperformed in a different sequence than that depicted below, as suited tothe specific environment, as will be apparent to one skilled in therelevant arts. Many of such implementations are contemplated to becovered by several aspects of the present disclosure. The flow chartbegins in step 250, in which control immediately passes to step 260.

In step 260, AP 110 receives a single MAC frame containing multiple IPpackets in the payload of the MAC frame. As an example, the MAC framecould be the MAC frame transmitted by STA 120 in step 230 of theflowchart of FIG. 2A. Control then passes to step 270.

In step 270, AP 110 disassembles the payload of the received MAC frameinto individual IP packets. In an embodiment, each individual IP packetrequires no modifications to any headers, etc., and therefore AP 110 canretransmit IP packets without requiring modifications to IP headers. APmay merely need to encapsulate each IP packet with any header assuitable for transmission on wired path 119. Control then passes to step280.

In step 280, AP 110 transmits each IP packet separately to thecorresponding destination. The destination addresses are contained inthe destination IP address fields of the IP packets. Control then passesto step 299, in which the flowchart ends.

Again, although the flowchart of FIG. 2B describes disassembly of thepayload of a MAC frame to obtain multiple IP packets which is are thenindividually (sequentially) forwarded to the corresponding destinations,the technique can be extended in general to disassembly of the payloadof a layer-2 packet to obtain multiple layer-3 packets, which are thenindividually transmitted to the corresponding destinations.

It may be appreciated that since multiple layer-3 packets are assembledinto the payload portion of a single layer-2 frame, STA 120 needs tocontend for the wireless medium only once, rather than for each layer-3packet as in the prior approach noted above. As a result, thetransmission of layer-3 packets at least in BSS 190 is renderedefficient.

The operations of the steps of the flowcharts of FIGS. 2A and 2B areillustrated next with examples.

4. EXAMPLES

FIG. 3 is a diagram illustrating the various layers of a communicationprotocol stack in STA 120. Communication protocol stack 300 is showncontaining physical layer 310, data-link layer (or MAC) layer 320,aggregation layer 330, network layer 340 and application layer 350.

Application layer 350 represents a communications component that allowssoftware applications executing in STA 120 to communicate with softwareapplications in other nodes, such as for example, servers 140A-140N.Application layer executes user applications, and receives data valuesgenerated by one or more of sensors 160A-160M. Application layer 350 mayprocess the data values suitably, and forwards each received data valueto network layer 340, along with the destination IP address to which thedata value is to be to be transmitted. Application layer 350 may forwardeach packet as the packet is received (or with a slight delay). In anembodiment, each type of data value is destined for a specificdestination. As an example, all temperature measurements may be destinedfor server 140A, pressure measurements may be destined to server 140B,etc.

Network layer 340 receives a data value, and forms an IP packet, withthe data value placed in the payload portion of the IP packet. Networklayer 340 stores the destination address to which the data value is tobe sent in the destination IP address field of the header of the IPpacket. Other fields of the header (e.g., total length of the IP packet)may suitably be programmed by network layer 340. As specified in RFC731, bits 16-31 of an IP packet are used to specify the total length ofthe IP packet, and network layer 340 places the corresponding length ofthe IP packet in this field, to enable AP 110 to identify IP packetboundaries and correctly disassemble an aggregated payload, as describedbelow.

Network layer 340 similarly forms other IP packets, each containing acorresponding data value as its payload and a corresponding destinationIP address in the destination IP address field of its header. While theIP packets are described as being formed within STA 120, it should beappreciated that IP packets may be received from the sensors generatingthe data values as well. Irrespective, network layer 340 assembles(gathers) multiple IP packets. Network layer 340 may also store multipledata values in the payload of a same IP packet if all such multiple datavalues are destined to a same destination. Network layer 340 forwardseach IP packet thus formed to aggregation layer 330. It is assumed thateach IP packet is encoded as a UDP packet, and accordingly the transportlayer is not shown between layers 340 and 350. However, alternativeembodiments may employ TCP for reliable delivery of each packet.

Aggregation layer 330 receives IP packets from network layer 330, andconcatenates multiple of such received IP packets to form a single(aggregated) payload. Aggregation layer 330 forwards the aggregatedpayload to MAC layer 320. In an embodiment, the size of the aggregatedpayload is limited to the maximum allowed size, i.e., maximumtransmission unit (MTU) specified by the IEEE 802.11 family ofstandards. It should be appreciated that MTU size may be easily obtainedsince packets destined to multiple destinations are being aggregated,and accordingly the wireless medium is efficiently used.

In addition, or in an alternative embodiment, aggregation layer 330aggregates only as many IP packets into a single payload as can be donebefore the expiry of an MTU timer. The timer may be started upon theavailability of the first IP packet to be incorporated into the frame,and if the maximum MTU size (noted above) is not reached before theexpiry of the MTU timer, the MAC frame is transmitted with as manypackets as are then available/assembled (at the expiration of thetimer).

MAC layer 320 receives an aggregated payload from aggregation layer 330,and forms a single MAC frame with the aggregated payload placed in thepayload of the single MAC frame. MAC layer 320 places the MAC address ofAP 110 in the destination address field of the MAC frame. An example ofa MAC frame formed by MAC layer 330 is shown in FIG. 4. Field 410 of MACframe 400 is the MAC frame header, and field 420 is the payload portionof MAC frame 400. IP packets 420A, 420B through 420N represent themultiple IP packets placed in the payload portion 420. In an embodiment,each of packets 420A, 420B through 420N is destined to a differentdestination. For example, packets 420A, 420B through 420N mayrespectively be destined to servers 140A, 140B through 140N. As anotherexample, packets 420A through 420N may be destined respectively for STAs130A through 130P (P assumed to equal N in this example).

When frame 400 corresponds to an IEEE 802.11 (WLAN) frame, frame 400 hasthe detailed structure shown in FIG. 5A. Frame 500 of FIG. 5A is showncontaining fields Frame Control 510, Duration/ID 520, Address_1 530,Address_2 540, Address_3 550, Sequence Control 560, Address_4 570, QoSControl 575, HT control 576, Frame Body 580 and FCS 590.

Frame Body 580 corresponds to payload 420 of FIG. 4. The rest of thefields together represent MAC header 410 of FIG. 4. A detaileddescription of the fields of packet 500 is provided in Section 8 of theIEEE Std 802.11-2012 document available with the InternationalTelecommunications Union (ITU). Only those fields as relevant to thisdisclosure are described herein. It is also noted that, in practice,frame 500 may contain more or fewer fields or proprietary modificationsdepending on the specific deployment environment.

MAC layer 320 places the BSSID of BSS 190, MAC address of STA 120 andthe MAC address of AP 110 respectively in address fields 530, 540 and550. Address field 570 is a “don't care”. Frame control field 510 isshown in greater detail in FIG. 6, which shows sub-fields ProtocolVersion 610, Type 620, Sub-type 630, To DS 640, From DS 650, More Frag660, Retry 670, Power Management 675, More Data 676, WEP 680 andReserved (Rsvd) 690. A detailed description of the fields of packet 500is provided in Section 8.2.4 of the IEEE Std 802.11-2012 documentavailable with the International Telecommunications Union (ITU). Onlythose fields as relevant to this disclosure are described herein. MAClayer 320 programs fields ‘To DS’ 640 and ‘From DS’ 650 to 1 and 0respectively.

In an embodiment, MAC layer 320 programs the ‘type’ field 620 and‘sub-type’ field 630 to indicate that frame 500/400 contains multiple IPpackets in its payload, to enable AP 110 to disassemble packet 500/400correctly. The specific values of the ‘type’ and ‘sub-type’ fields canbe any that are not currently specified for use by the IEEE 802.11standard. As an example, the value of the ‘type’ field can be 10(binary), and the value of the ‘sub-type’ field can be 1101 (binary). Inan alternative embodiment, MAC layer 320 programs fields 620 and 630with a ‘regular’ value (for example ‘type’ field as 10 (binary), and‘subtype’ field as any value that has data/QoS data combination, forexample 0000 (binary)), and indication that frame 500/400 containsmultiple IP packets is provided in an information element (IE) field ofan association request packet sent by STA 120 to AP 110 prior to joiningBSS 190.

MAC layer 320 also performs medium access operation (e.g., CSMA/CA)specified by the corresponding wireless standard, and forwards frame500/400 to physical layer 310. Physical layer 310 transmits frame500/400 on the wireless medium via antenna 125.

The respective layers of the communication protocol stack 700implemented in AP 110 are shown in FIG. 7. Communication protocol stack700 is shown containing physical layer 710, data-link layer (or MAC)layer 720, de-aggregation layer 730, and network layer 740. Theoperations at the respective layers of stack 700 upon receiving frame500/400 are noted next.

Physical layer 710 receives, via the antenna of AP 110, MAC frame500/400, and forwards the frame to MAC layer 720. MAC layer 720 inspectsfields 620 and 630 of the MAC header of frame 500/400 to determine ifmultiple IP packets are present in the payload of the MAC frame. Iffields 620 and 630 indicate that the payload of the MAC frame containsmultiple IP packets, MAC layer 720 strips the MAC header off frame500/400, and forwards the aggregated payload portion of the MAC frame tode-aggregation layer 730. Alternatively, MAC layer 720 may rely onindication received during association (in an IE field of theassociation request frame) of STA 120 with AP 110, as well as the sourceaddress field (540 of FIG. 5) to determine whether the MAC frame 500/400contains multiple IP packets or not. If MAC layer 720 determines thatframe 500/400 is a ‘normal’ frame (i.e., does not contain multiplepackets in its payload), MAC layer 720 forwards the payload directly tonetwork layer 740.

De-aggregation layer 730 disassembles the aggregated payload containingmultiple IP packets into individual IP packets, and forwards each of theindividual IP packets to network layer 740.

For each of the individual IP packets received from de-aggregation layer730, network layer 740 determines, based on the destination IP addressin the corresponding IP packet and a routing table (not shown), thenext-hop device (or specifically, the interface coupling to such nexthop device) to which the IP packet is to be transmitted. Network layer740 instructs MAC layer 720 to transmit each packet (and directly, i.e.,without sending them to de-aggregation layer) to the determined next-hopdevice in case the packet is being transmitted on the wireless medium.

MAC layer 720 adds appropriate layer-2 headers to each of the IP packetsreceived from network layer 740, and forwards each of the resultinglayer-2 frames to physical layer 710. For example, if a received IPpacket is destined for a STA in BSS 190, then MAC layer 720 adds an IEEE802.11 header. On the other hand, if the next-hop device for a receivedIP packet is a device in internet 150, then MAC layer 720 adds an IEEE802.3 header.

Physical layer 710 forwards each of the layer-2 frames along the path(coupled to the determined interface) to the destination.

As an example, when IP packets 420A through 420N are respectivelydestined for servers 140A through 140N, each of IP packets 420A through420N would respectively be forwarded on the corresponding route (path119) to servers 140A through 140N.

The description is continued with an illustration of the implementationdetails of a wireless device in an embodiment.

5. Wireless Device

FIG. 8 is a block diagram showing the implementation details of awireless device in an embodiment of the present disclosure. STA 120 aswell as AP 110 of FIG. 1 can be implemented as wireless device 800.Wireless Device 800 is shown containing processing block 810,input/output (I/O) block 820, random access memory (RAM) 830, real-timeclock (RTC) 840, battery 845, non-volatile memory 850, sensor block 860,transmit (TX) block 870, receive (RX) block 880, switch 890, and antenna895. The whole of wireless device 800 may be implemented as asystem-on-chip (SoC), except for battery 845 and antenna 895.Alternatively, the blocks of FIG. 8 may be implemented on separateintegrated circuits (IC). Terminals 846 and 899 respectively represent apower and a ground terminal.

Battery 845 provides power for operation of wireless device 800, and maybe connected to the various blocks shown in FIG. 8. While wirelessdevice 800 is shown as being battery-powered, in another embodiment,wireless device 800 is mains-powered and contains correspondingcomponents such as transformers, regulators, power filters, etc. RTC 840operates as a clock, and provides the ‘current’ time to processing block810.

I/O block 820 provides interfaces for user interaction with wirelessdevice 800, and includes input devices and output devices. Sensor block860 may contain one or more sensors (e.g., sensors 160A-160M of FIG. 1),as well as corresponding signal conditioning circuitry, and provides toprocessing block 810, measurements/values of physical quantities such astemperature, pressure, etc., sensed via wired path 862 or wireless path863. Sensor block 860 may perform analog-to-digital conversion of themeasurement/values prior to forwarding the measurements/values toprocessing block 810. When AP 110 is implemented as wireless device 800,sensor block 860 may not be included.

Antenna 895 (corresponds to the antennas of AP 110 or STA 120), andoperates to receive from, and transmit to, a wireless medium,corresponding wireless signals (e.g., according to IEEE 802.11 (WLAN)standards). Switch 890 may be controlled by processing block 810(connection not shown) to connect antenna 895 to one of blocks 870 and880 as desired, depending on whether transmission or reception ofwireless signals is required. Switch 890, antenna 895 and thecorresponding connections of FIG. 8 are shown merely by way ofillustration. Instead of a single antenna 895, separate antennas, onefor transmission and another for reception of wireless signals, can alsobe used. Various other techniques, well known in the relevant arts, canalso be used instead.

TX block 870 receives, from processing block 810, packets (such as thoseof the parallel data streams described above) to be transmitted on awireless signal (e.g., according to a wireless standard such as IEEE802.11), generates a modulated radio frequency (RF) signal (according tothe standard), and transmits the RF signal via switch 890 and antenna895. TX block 870 may contain RF and baseband circuitry for generatingand transmitting wireless signals, as well as for medium accessoperations. Alternatively, TX block 870 may contain only the RFcircuitry, with processing block 810 performing the baseband and mediumaccess operations (in conjunction with the RF circuitry).

RX block 880 represents a receiver that receives a wireless (RF) signal(e.g., according to IEEE 802.11) bearing data and/or control informationvia switch 890, and antenna 895, demodulates the RF signal, and providesthe extracted data or control information to processing block 810. RXblock 880 may contain RF as well as baseband processing circuitry forprocessing a WLAN signal. Alternatively, RX block 880 may contain onlythe RF circuitry, with processing block 810 performing the basebandoperations in conjunction with the RF circuitry.

Non-volatile memory 850 is a non-transitory machine readable medium, andstores instructions, which when executed by processing block 810, causeswireless device 800 to operate as STA 120 when STA 120 is implemented aswireless device 800, and as AP 110 when AP 110 is implemented aswireless device 800. In particular, the instructions enable STA 120 andAP 110 to operate respectively as described with respect to theflowcharts of FIG. 2A and 2B.

RAM 830 is a volatile random access memory, and may be used for storinginstructions and data. RAM 830 and non-volatile memory 850 (which may beimplemented in the form of read-only memory/ROM/Flash) constitutecomputer program products or machine (or computer) readable medium,which are means for providing instructions to processing block 810.Processing block 810 may retrieve the instructions, and execute theinstructions to provide several features of the present disclosure.

Processing block 810 (or processor in general) may contain multipleprocessing units internally, with each processing unit potentially beingdesigned for a specific task. Alternatively, processing block 810 maycontain only a single general-purpose processing unit. Processing block810 may execute instructions stored in non-volatile memory 850 or RAM830 to enable wireless device 800 to operate according to severalaspects of the present disclosure (as corresponding to wireless stationor AP), described above in detail.

6. CONCLUSION

While various embodiments of the present invention have been describedabove, it should be understood that they have been presented by way ofexample only, and not limitation. Thus, the breadth and scope of thepresent invention should not be limited by any of the above-describedembodiments, but should be defined only in accordance with the followingclaims and their equivalents.

What is claimed is:
 1. A method performed in a wireless station of awireless network, said method comprising: generating a single layer-2frame containing a plurality of layer-3 packets, with each layer-3packet of said plurality of layer-3 packets being destined to acorresponding destination of a plurality of destinations; andtransmitting said single layer-2 frame to an access point (AP) of saidwireless network.
 2. The method of claim 1, wherein said wirelessnetwork is according to IEEE 802.11 standards, each layer-3 packet is anIP packet and said single layer-2 frame is a medium access control (MAC)frame.
 3. The method of claim 2, wherein each of said IP packetscontains an IP destination address of the corresponding destination. 4.The method of claim 3, wherein said generating generates a sequence oflayer-3 packets at respective times instances of a sequence of timeinstances, and includes only some of said sequence of IP packets as saidplurality of layer-3 packets without violating a maximum transmissionunit (MTU) specified by said wireless network.
 5. The method of claim 4,wherein said generating includes only those of said sequence of IPpackets which are formed before expiration of a timer.
 6. The method ofclaim 5, wherein said AP upon receiving said MAC frame containing saidheader, disassembles said payload into individual IP packets, andtransmits each IP packet towards a corresponding destination.
 7. Themethod of claim 6, wherein said wireless station associates with said APto join said wireless network by exchanging a sequence of messages,wherein a first message of said sequence of messages sent by saidwireless station to said AP contains a field for said wireless stationto indicate that multiple IP packets would be contained in subsequentMAC frames, wherein said disassembling and transmitting of each IPpacket are performed by said AP in response to said first message. 8.The method of claim 6, wherein said MAC frame contains a header and apayload, said header indicating that said payload contains multiple IPpackets, wherein said disassembling and transmitting of each IP packetare performed by said AP in response to said header indicating that saidpayload contains multiple IP packets.
 9. A non-transitory machinereadable medium storing one or more sequences of instructions in awireless station, wherein execution of said one or more instructions byone or more processors contained in said wireless station enables saidwireless station to perform the actions of: generating a single layer-2frame containing a plurality of layer-3 packets, with each layer-3packet of said plurality of layer-3 packets being destined to acorresponding destination of a plurality of destinations; andtransmitting said single layer-2 frame to an access point of saidwireless network.
 10. The non-transitory machine readable medium ofclaim 9, wherein said wireless network is according to IEEE 802.11standards, each layer-3 packet is an IP packet and said single layer-2frame is a medium access control (MAC) frame.
 11. The non-transitorymachine readable medium of claim 10, wherein each of said IP packetscontains an IP destination address of the corresponding destination. 12.The non-transitory machine readable medium of claim 11, wherein saidgenerating generates a sequence of layer-3 packets at respective timesinstances of a sequence of time instances, and includes only some ofsaid sequence of IP packets as said plurality of layer-3 packets withoutviolating a maximum transmission unit (MTU) specified by said wirelessnetwork.
 13. The non-transitory machine readable medium of claim 12,wherein said generating includes only those of said sequence of IPpackets which are formed before expiration of a timer.
 14. Thenon-transitory machine readable medium of claim 13, wherein said AP uponreceiving said MAC frame containing said header, disassembles saidpayload into individual IP packets, and transmits each IP packet towardsa corresponding destination.
 15. The non-transitory machine readablemedium of claim 14, wherein said wireless station associates with saidAP to join said wireless network by exchanging a sequence of messages,wherein a first message of said sequence of messages sent by saidwireless station to said AP contains a field for said wireless stationto indicate that multiple IP packets would be contained in subsequentMAC frames, wherein said disassembling and transmitting of each IPpacket are performed by said AP in response to said first message. 16.The non-transitory machine readable medium of claim 14, wherein said MACframe contains a header and a payload, said header indicating that saidpayload contains multiple IP packets, wherein said disassembling andtransmitting of each IP packet are performed by said AP in response tosaid header indicating that said payload contains multiple IP packets.17. An access point (AP) of a wireless network, said AP comprising: aprocessing block, a memory, and a transmitter circuit, said memory tostore instructions which when retrieved and executed by said processingblock causes said STA to perform the actions of: receiving a singlelayer-2 frame containing multiple layer-3 packets in a payload of saidsingle layer-2 frame, wherein each of said multiple layer-3 packets isdestined to a different destination; disassembling said payload intoindividual layer-3 packets; and transmitting each of said individuallayer-3 packets separately towards a corresponding destination.
 18. TheAP of claim 17, wherein said wireless network is according to IEEE802.11 standards, each layer-3 packet is an IP packet and said singlelayer-2 frame is a medium access control (MAC) frame.
 19. The AP ofclaim 18, wherein said single layer-2 frame is transmitted by a wirelessstation, wherein said wireless station associates with said AP to joinsaid wireless network by exchanging a sequence of messages, wherein afirst message of said sequence of messages sent by said wireless stationto said AP contains a field for said wireless station to indicate thatmultiple IP packets would be contained in subsequent MAC frames, whereinsaid disassembling and transmitting of each IP packet are performed bysaid AP in response to said first message.
 20. The AP of claim 18,wherein said MAC frame contains a header and a payload, said headerindicating that said payload contains multiple IP packets, wherein saiddisassembling and transmitting of each IP packet are performed by saidAP in response to said header indicating that said payload containsmultiple IP packets.